A second blueberry fertilizer plication schedule should take place in late spring to allow the formation of large and juicy berries. Some soils may contain all that is needed for vigorous raspberry … Reviews:7 Best Fertilizer For Blueberries In 2020 Reviewed 1.Espoma HT18 Holly Tone for For Blueberries… It’s not just about blueberries and you can use this product for other familiar fruits like raspberries … If one of the best fertilizers for blueberries is applied, your bushes can thrive, produce plump, juicy fruits, and yield bumper harvests for 40 or 50 years to come. It is a good idea to test the soil prior to planting raspberries. The Best Time for Fertilizing Raspberry Bushes. Here are the best fertilizers for blueberries … and cvs.) This best fertilizer for blueberries is also said to be enhancing the microorganism growth within the plants and its granules based formula works perfectly for acid-loving plants like Blueberries. But mulch around the plants is more important than fertilizer to growing healthy raspberries. Raspberries will accept any ordinary balanced fertilizer, such as 10-10-10 in small amounts. Or you can use a fertilizer designed … grown in zones 3 through 9. Very high nitrogen fertilizers… Blueberries thrive with fertilizers for acid-loving plants, such as rhododendrons (Rhododendron spp. Garden soil preparation for raspberry bushes should begin months to a year before planting.